<em>I'm sorry, it says check all that apply, however there are no choices given. You should edit, and add the multiple choice answers.</em>
My Answer:
Well if the masses of two objects were both decreased, it would result in a decrease in the gravitational force. So I guess the two objects masses would need to be decreased.
1. Cenozoic ERA
2. Mesozoic ERA
3. Paleozoic ERA
Power=Energy
72,000/60 = 1200 watts
:)
